You can configure the UVM1000 to sum CFMs over the RS-485 network and output the summed equivalent on the Vo of the designated primary unit. The designated primary unit uses hardware address 15. Secondary polled units are units with address 16 and onwards. The primary unit specifies how many units to poll from address 16 and onwards.
About this task
- Do not combine exhaust and supply valves in same RS-485 loop when UVMnet summing is available. You can only use loops exclusively for supply or exhaust for summing.
- It is best practice you sum spaces with less than 10 devices. Set the parent device, typically the general exhaust, to hardware address 15.
- The parent device control signal scaling is determined by the valve size and ganged values of parent device.
- Ensure you connect all exhaust valves in a space with a RS-485 loop. Ensure you address the valves to Parent Device Address 15 and Polled Devices 16 to 32.
- Set the first fume hood for hardware address 14 with dip switch 2,3,4-ON/ 1-OFF. Connect with the UVM Cable and set the secondary Address to 16.
- Set the second fume hood to hardware address 13 with UVM dip switch 1,3,4-ON/ 2-OFF. Connect with UVM Cable and set the secondary Address to 17. You can now communicate with all three exhaust valves at addresses 15, 16, and 17 for summing.
- Set the Summing Loop Feedback scaling for summed scaling factors for all valves in loop. For example, three single 8 in. valves have a feedback scaling factor of 2400 CFM.
Ensure that you configure Vo= 10 VDC to 2400 CFM. Using the UVM Configuration Tool, click User Settings Tab> Vo=10v. To write the setting, click Set 10v SUM CFM. See the following table for more information on value inputs.
Table 1. Value inputs and locations Value amount Value location 2300 CFM Single valve scaling factor 1 Ganged value 2171 CFM Preferred CFM setpoint 9.439130435 VDC Direct acting control signal 0.560869565 VDC Reverse acting control signal 2300 CFM Analog Output/Input scale 0 VDC to 10 VDC UVM feed-back signalNote:
- A reverse acting valve is controlled with a reverse acting analog output.
- All 0 VDC to 10 VDC feed-back signals are direct acting.
- The Parent Device control signal scaling is determined by the valve size and ganged values of the Parent Device.
- Determine if you need a feedback calibration by error verification in Control Signal voltage and Indicated CFM.